Special Purchase. Nobelsport brand made in Italy. Please note, we have found a small percentage of this ammo where it is marked as 2x.650 cal ball on the 10 round boxes, however the ammo is still the correct single ball type. 250 rd case - 12 Gauge 1oz .650 caliber Round Ball 1400FPS 2.75 inch Ammo. This is similar to a slug and contains one large 1 ounce round ball type projectile for deep penetration. This ideal blasting ammo for the Siaga or any tactical shotgun. I shot some of this ammo in my Siaga 12 and it fed and functioned perfect in both the factory 5 round mag and the Pro-Mag 20 round drum. Accuracy seemed to be good but no specific measure was taken.